(1) Field of the Invention
The present invention relates to a method and system for spreading a tow of fibers using energy from a gas vibrating means adjacent to the fibers. In particular, the present invention relates to a method and system where the tow of fibers zig-zag over spaced apart rods adjacent to the diaphragm of a speaker while maintaining a slack in the tow to allow spreading of the tow of fibers by movement of the gas above the speaker and around the tow of fibers.
(2) Prior Art
U.S. Pat. No. 3,704,485 to Hall describes a method and apparatus for spreading a tow of fibers using a speaker or other gas vibrating means adjacent to the fibers. The tow of fibers passes over the speaker under low tension, essentially by tension created by the weight of the fibers, and is spread by the sound waves in the gaseous medium, usually air, created by the speaker. The Hall method works well; however, the tow of fibers are unrestrained while being acted upon by the sound waves and can be easily damaged. Also, there is no means described by Hall for maintaining the spread of the fibers over the speaker so that the maximum spread is achieved. Also Hall uses internally wound spools for feeding the tow of fibers which provide little or no tension on the fibers of the tow.